Variable output mixing system



Oct. 25, 1949. K. A. RAYPHOLTZ VARIABLE OUTPUT MIXING SYSTEM Filed April 24, 1946 Patented Oct. 25, 1949 VARIABLE OUTPUT MIXING SYSTEM Kenneth A. Raypholtz, Marion, Ind., assignor to Overmander Machine, Inc., Marion, Ind., a corporation Application April 24, 1946, Serial No. 664,490

1 Claim.

and like purposes.

The chief object of this invention is to insure adequate and proper mixing determinable by the character of the aggregate utilized and the bituminous material utilized and to provide for the proper mixing thereof and the maintenance of a rated output so that the device can be utilized for the continuous production of a bituminous mixture according to predetermined specifications and which will comply therewith.

The chief feature of the invention resides in the provision of a pug mill wherein the housing is rotated and a central screw therein can be rotated and the two rotated at difierent speeds and in the opposite directions, if desired, the speed difierential providing the correct mixing of the aggregate and the bituminous material so that the bituminous mixture complies with the predetermined specifications.

Other objects and features of the invention will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawings and the following description and claim:

In the drawings Fig. 1 is an elevational view of an embodiment of the invention, parts being broken away to show the same and other parts in central section, the broken away portions be-. ing more particularly the adjacent ends of the pug mill proper and the bituminous material supply device and the discharge end of the pug mill structure.

Fig. 2 is a transverse sectional view through the pug mill structure.

In Fig. 1 of the drawings l indicates the discharge from an aggregate drier of any suitable type and the same discharges into the intake ll of a bituminous applicator mounting a central shaft l 2 at the discharge end by means of a bearing structure l3 and at the intake end by means of the bearing and seal [4.

The exteriorly exposed end of the shaft 12 may include driving means l5 operatively associated with a variable speed motor l6 which may be independently controlled to insure a, predetermined speed of rotation of the shaft 12. The shaft l2 has secured to it the primary flight l1 and the supplemental or end flight l8, the two having their adjacent ends spaced by the forward bearing l3 aforesaid.

The screw enveloping tube 19 at its rearward end communicates with the housing portion II and its forward end is biased and open as at 20. The upper portion of this shell [9 is suitably apertured as at 2| and closing the same is a cover structure 22, the latter including a bituminous supply channel or header 23 having the aligned and spaced spray nozzles 24.

There are at least two parallel series of spray nozzles and same preferably are substantially coextensive with the cover 22 and the several series have a general direction of discharge towards each other. The supply for the liquid bituminous material is intentionally omitted for clearness.

It will be quite obvious that if a properly dried aggregate of the desired proportions is continuously supplied as at H to the intake end of the tube [9 that, as the screw therein is rotated, this aggregate is advanced through the tube. It is also carried upwardly and rotated by the screw. In its rotation the aggregate immediately beneath the spray nozzles is supplied with the liquid' bituminous material in a regulated amount. Therefore, the resulting mixture as it discharges from the biased end 20 of the device aforesaid includes the proper amount of bituminous material and the proper amount of aggregate in the proper proportions.

However, as will be readily apparent, despite the spraying of the bituminous material upon the advancing aggregate, certain portions of the aggre'gate will be excessively coated and other portions may be devoid of bituminous material coating, or deficient in such coating. The mixture, such as it is, when discharged at 29 thus will comply with the specific requirements as to aggregate and bituminous material proportions but generally'will not comply with the requirement that the same constitute a substantially homogenous mixture wherein the bituminous material is uniformly distributed throughout the aggregate.

Accordingly there is provided an additional mixer that takes the variously mixed bituminous material and aggregate from the discharge 20 and then further mixes the same so that uniformity and homogenization of the final bituminous mixture is attained and is maintained during the continuous operation of the device herein illustrated as long as a controlled supply of bituminous material and a controlled supply of properly proportioned aggregate is supplied to the spray device.

The means for supplying the same, and which form nopart of the present invention, may be of any desired or required character. Devices suitable therefor are illustrated, described and includes the vanes 26 adjacent a central bearing structure '2! carried by and within the said housing and providing a central bearing 28 for a shaft 29.

Adjacent the immediate lower end 30 of the housing 25 and the biased end 26, the biasing corresponding to the end 36 aforesaid, is a sleeve structure 3i in which the screw end l8 rotates and the housing 25 rotates. Thus, material discharged from the tube it by the flights l1 and l8 enters the open end of the rotatable housing 25 and is caused to advance therein by means of the vanes 26.

The shaft 29 mounts inclined blades 32 as shown. These blades are generally radially disposed and diametrically positioned with respect to each other and each is inclined at an angle approximately 45. In other words, they are biased, as it were.

Interposed between successive diametrically disposed blades 32 are other blades 33 which are also diametrically disposed and they clear the adjacent blades and terminate short of the shaft 29 so as to clear it as well. These blades 33 at their outer ends are rigidly secured to the interior of the rotatable housing '25.

The upper end of the shaft 29 is supported in a housing supported bearing 64 at the upper end of the housing 25. The shaft 29 projects beyond that upper bearing 34 and herein is shown provided with a sprocket gear 35 meshing with chain 36, in turn meshing with sprocket pinion 31, all of the aforesaid being enclosed, as by the stationary housing or elbow.

The sprocket 31 is carried by the upper end of the lay shaft 36, which is rotatably supported in the bearing 39. Interposed between sprocket 3'! and the bearing 39 is the roller 46 to which reference will be had hereinafter.

The lower end of the lay shaft is rotatably mounted in the stationary bearing 4i and adjacent the immediate end thereof it mounts a roller 42 similar to roller 4!! and aligned therewith. The immediate end of the shaft 38 mounts a helical gear 43 meshing with another gear of like character 44 carried by a shaft 45 suitably supported in the stationary bearing 46 and the same may be driven by a variable speed motor diagrammatically illustrated herein and indicated by the numeral 41.

Adjacent the bearing 4| and rigid with the rotatable housing 25 is the sprocket structure 48 with which meshes chain 49, in turn meshing with a sprocket pinion 56 carried by the shaft supported in the bearing 4! as at Ma. The opposite end of the shaft 5! mounts the helical gear 52 and same meshes with a similar gear 53' carried by a shaft 54 also rotatably supported in the bearing 46 as at 55.

The shaft 54 is driven by a variable speed motor diagrammatically illustrated herein and indicated by the numeral 56. Thus motor 56 determines the speed of rotation of the housing 25 and the motor 4'! determines the speed of rotation of the shaft 29. Thus the speed of rotation of the screw l'l-IB is determined by the motor IS, the speed of rotation of the vanes 33 is determined by the motor 56 and the speed of rotation of the vanes 32 is determined by the motor 47!.

Itwill be obvious that the shafts 54 and 45 can be rotated in opposite directions and also that the rates of rotation may coincide or be varied as desired or required and that such change in speed or speeds can be effected while the apparatus herein described is in operation. Also, the speed of the screw in the tube I9 can be varied if desired or required and while that device is in operation.

Accordingly, all of the aforesaid objectives are capable of accomplishment by the apparatus hereinbefore described.

It will be noted that the pug mill structure is inclined upwardly so that trucks and the like can be backed beneath the discharge upper end and the pug mill structure is of cantilever supported type. Herein at each side of the housing 25 there are provided supporting channels 60 and these are shown most clearly in Fig. 2.

Rigid with channels 66, near the ends thereof, are the upper substantially semi-circular yokes 6| ribbed as at 62 and ofiset for channel clearance at 63. Complementary semi-circular lower yokes 64 are inwardly flanged as at 65 and terminate in offset portions 66 by which same are secured to said channels.

The drum exterior includes peripherally arranged channel sectioned member 61 and same has associated therewith the roller 46 flanged at Ma and rotatably supported by lay shaft 38. Similar rollers 68, flanged at 68a, are rotatably supported by trunnions 69 mounted in bosses l0 rigid with yoke member 64.

The periphery of rollers 40 and 68 rides the periphery of member 61 and the flanges of said rollers hold up, as it were, said shell or housing 25. Both ends thereof are similarly supported and same is rotated by sprocket 48 and chain 49.

Thus the mechanism described is capable of combining or mixing the rated output of the mechanism for the housing and inner screw can be differently rotated and at various relative speeds over a wide range, so that predetermined properly mixed rated output is obtained therefrom.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein, as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claim.

The invention claimed is:

In combination with an aggregate feeding and bituminous material supply apparatus, a mixer adapted for continuous mixing including a rotatable housing, a coaxial screw therein, the apparatus substantially continuously discharging to one end of the housing, the resulting bituminous mixture discharging from the opposite end thereof, and. adjustable driving means for adjustably and differentially rotating the housing and screw, the aggregate feeding and bituminous supply apparatus comprising a housing and a rotatable 5 agitator type conveyor therein, the latter terminating inmediately adjacent the discharge of the apparatus housing, the last mentioned discharge being coincident with the intake of the rotatable housing, the two housings disposed in end to end relation including an obtuse angular relationship therebetween.

KENNETH A. RAYPHOLTZ.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 377,256

France Sept. 3, 1907 

